Monoplane flying boat



July 29, 1930. A. ROHRBACH 1,771,512

I MONOPLANE FLYING BoA'r Filed July 2L" I927 d M ;1 Fi .1. 3 H Y 2 Q k f e f2 Fig.2 0'

I If a Patented July 29, 1930 :uNrrE srA Es PATENT F ADOLE nonnnnon, orwrnmnnsnonr, NEARLBERLIN,"GERMANY, nssienoa To noHR- BACl-I PATENTS conronarron, A conronnrron or na' AwAnn MonoPLAnn FLYING BoA'r Application filed July 21, 1927, Serial No. 207,393, and in Germany July 13, 1926'.

The invention relates to a monoplane flying-boat, characterized by the boat-hull carrying the tail plane unit and wing, which latter supports the driving means, and be ing provided with a sharp-edged bow and a slightly inclined and elevated stem; the forecastlc, containing one or more cockpits for the crew, preferably considerably overtopping the remaining deck portionand substantially merging, into the leading edge of the wing, in the direction of the inclination of the latter, whilst the wing trailing edge ends on a level with the central. heat deck or somewhat below the same. lVith the forecastle curved, its lat eral edges merge into the bottom surface of the wing at the Wing leading edge, whilst the central portion of the forecastle is attached to thetop surface of the wing. 5

According to the present invention it is possible to design a monoplane flying-boat of perfect seaworthiness and able to cut the waves of a heavy sea without washing over the forecrstle. Further advantagesconsist in that this new type of flying-boathas, owing toits very small air resistance, excellent flying properties, and permits of good andunobstructed vision in substantially all directions.

For a better understanding of the invention, reference may be had to the accompanying drawing which show, by way of example, several embodiments of the present invention, wherein: i

1 and 2 represent one embodiment in side elevation and plan View.

Fig. 3 is a front elevation with indicated body planes. a

Fig; 4 is a front view "of a boat with modified bow. I

- Figs. 5 and 6 are further forms of embodimentsin side elevation. j i

The hull of the monoplane seaplane according to Figs. 1 and 2 consists of a boat-body a, carrying at the rear partthe tail plane unit 7) and substantially centrally thereof the wing c. Cl ligh above the latter twoengines are arranged laterally and symmetrically to the vertical central plane of thecraft and supported on struts. Underneath each wing halfa stabilizing float d isarranged and 1.1 either against the alone or .ga'instfboth'wing and hull, said float functioning to impartto the floating craft a rather great metacentric height,- and to the craft at startinga considerable dynamic buoyancy. The boat is comparatively narrow and elongated. Two steps e e' -are providedf The bottom part f in frontof the first step 6. is considerably inclined towardsthe keel g, which merges towards the ,more elevated chime, into a curve]; (concavedownwardly). This construction of the bow facilitates take off and alighting by deviating the jwatercu'rrent. The bottom part-elf, ff) aft of the steps are rather fiat-surfaces with very small, ifany, inclination.

The keelg of the bottom f? terminates, with. ajsharp-edged bow, into' a rather precipitous erect stem 2', the top part of which'issituated above the dotted line indicating the; level of the central and rear boat deck 9', so that the forecastle 7r, overtops or projects above the level of the latter. Theforecastle edges k merge into the wing bottom surface, close to the leading edge 0 of the wing, whilstthevertex of the forecastle curvature issituated 1n the same plane as the wing top surface. 76

indicates the pilots and mechanics cockpit.

Theiwing trailing edge 0 terminates be ow the central boat'deck j. q

According to Fig. 3 the side surfaces of the how are substantially straight with but little inclination to the vertical, If it seems advisable the bow can be designed pronounced cruiser how, by using curved tapered bow frame members in order to obtain the extensively overtopping or overhanging forecastle la, which prevents the waves and spray Water washing over. Fig. t is an embodiment ofthe saidformof construction. The Stem 2' can, with either form of construction, be curved or inclined forwardly, as per Fig. 1, dotted line, instead of being straight up.

The form ofconstruction represented in a Fig. 5 shows, a boat of thegeneral construe;

tion shown in Fig. 1 but with the trailing edge 0 of the Wing c terminating inthe plane of the deck This is'effected by elevating the forecastle is still further with reference to the forecastle situated in the plane of the Wing chord. The vertex of the forecastle curvature ends in the central air-threads convergency point of the wing arrangement is recommended in the event that special value should be attached to favourable .air flow conditions, whereas, to ob,- tain the best possible View backwards, the vertex of the curvature should preferably be situated in the plane of thewing top surface.

Another advantageous feature'of this f-orm of construction resides in the wing 0 being detachably attached in the plane of the boat deck, so that the wing bottom surface and deck plane are continuous. The juncturesor attaching means are represented diagramniatically' by 0, preferably including screw devices and aresituated'in the planes of two Wing main girders. The float bracing struts arefcarried to the main girders as illustrated.

According to the form of construction of Fig. 6 an elongated boat body is represented,

with a wing consisting of a box-shaped central'portion and leadingand trailing edges impartingthe final sectional shape to the wing, said central portion belng accommodated-in an aperture or recess, opening towards the deck, formed in the correspondingly higher raised boat-body. The connection of boatand wing should, with this latter arrangement, also be detachable, so that, with he Wing attached, t e ransvrsewal s of the latter carry the forces occurring the boat deck beams, Inthis case the deck is sub stantial y, s raight, f om-b w to st m, the

lines thereof" being only slightly bent with the wing top surface, the forecastle and the rear part of the decksituated in substantially the same plane. a

It is notessential, according to the inven tion, whether the wing is entirely ofthe can} tilever type or braced or. supported by means of wires or struts. If desired,the how can be made, with every form of construction, so

. long that in front of thepilots cockpit 74? another hatchway for one member of the crew can be arrangedat a suitable distance, as shown in Fig. 6. z

f course the edges of the forecastleneed r not be attached to or merge into the wing chord incase of the bow walls merging into th fo ecast eith con in ou i r at re- In, another form of construction the edges of the curved forecastle terminates in the central air thread convergency point of the vertex in the wing top surface. Pusheror tractor; screws can be provlded 1n all cases w th equal efficiency. a

After having thus described the nature of my said invention and. inlwhatrina nner the sarneis to be performed, I declare that what I claim is: v

'1. In a monoplane flying. boat the combina tion of a boathull of elongated form having a bow terminating in a sharp cutting edge The latter 1 surfaces substantially above the plane of the rear deck.

2. A flying boat of the character set forth in claim 1 wherein-the elevated front deck is formed with a curved surface, its upper sur face merging into the nose of the Wing.

3. A flying boat of the character set forth in claim 1 wherein the elevated front deck is formed with a curved surface, the upper part of which merges into the center of the leading edge of the wing. 4. 'A flying boat of the character set forth in claim 1 wherein the elevated front deck is formed with a curved surface, and the edges formed by the front deck and side Walls of the hull substantially intersect the front end of the wing chord.

5; A flying boat of the character set forth in claim 1 wherein the elevated front deck is formed with a curved surface, the uppermost part of which forms substantially a continuation of the uppermost surface of the wing. I

6. A monoplane flying boat having a sharpbowed hull adapted to take load substantially throughout its length and to carry the tail plane unit, with the plane carrying the engine or engines and resting on the hull, and with a high stem joining the keel with a sharp curve, the forward deck, open for a cock-pit or cock-pits, being raised above the level of the mid ship and aft deck, said forward deck merging into the fore part of the Wing, and

the trailing edge of the plane terminating at apoint atleast not above the level of the mid ship portion of the deck.

7. In a monoplane flying boat'the combination of a boat hull of elongated form having a bowterminating in a sharp cutting edge with a high stem forming with the keel of the boat a sharp inclination, with the monoplane wings directly attached to the hull at the upper deck and having thick sections at their junction therewith and a power plant elevated substantially above the level of both the boat hull and the monoplane wings.'

8. In a monoplane flying boat of the character set forth in claim 7 wherein the hull is of narrow elongated form and has substantially straight vertical side lines from the chines to the rim of the boat.

- 9. In a monoplane flying boat the combination of a boat hull of elongated form having a bow terminating in a sharp cutting edge with a high stemforming with the keel of the boat a sharp inclination, the forward deck of the hull being elevated above the level of the aft deck, with the monoplane wings directly attached to the hull and having thick sections at their junction therewith, the elevated fore deck merging into the Wings.

10. A flying boat of the character set forth in claim 9 wherein the elevated forward deck which merges into the wing section is formed with other than a plane surface, the rim of the fore deck approximately intersecting at its rear ends the wing chord.

11. A monoplane of the character set forth in claim 9 wherein the wings are disposed above the level of the aft deck, the upper surface of the fore deck merges into the leading edge of the wing, the rim of the fore deck formed by the fore deck and side walls lying in the plane of the wing chord and the wing chords having a positive angularity with reference to the edges of the aft deck.

12. Ina monoplane of the character set forth in claim 9 wherein the wings are elevated above the plane of the level of the aft deck with their root portions demonntably attached to the hull, the upper surface of the elevated fore deck merging into the leading edge of the wing, the fore deck rim formed by the front deck and side walls of the hull being approximately in the direction of the wing chord.

13. In a monoplane flying boat the combination of an elongated boat hull having a bow terminating in a sharp cutting edge with a high stem forming with the keel of the boat a sharp inclination and the side walls of the hull extending without sharp breaks in contour from the chines to the deck, the latter being substantially planar. at its after part and the fore deck being elevated above the level of said after deck; with the monoplane wings directly attached to the hull and havmg thick sections at their junction therewith,

' said monoplane wings having the maj or part of their section positioned above the level of the after deck and bridging the gap between the elevated fore deck and the aft deck, and a power plant supported substantially above the level of both the monoplane wings and the flying boat, the fore deck containing means for observation by the crew and merging into the forward part of the wing.

14. A monoplane of the character set forth in claim 13 wherein the rims at the fore deck formed by the fore deck and the side walls of the hull lie in an approximate prolongation of the wing chord and the monoplanewings are of full cantilever construction.

15. A flying boat of the character set forth in claim 13 including twodisplacement pontoons disposed laterally of the hull which functions both as transverse stabilizing floating means and hydro-dynamic and buoyant devices for taking off.

16. A flying boat of the character set forth in claim 13 including two displacement'pontoons disposed laterally of the hull which function both as transverse stabilizing floathull is provided with a step in the vicinity of the wings, the chines are elevated above the keel and the surface of the boat hull between the chines and the keel are concaved downwardly.

'17. A flying boat of the character set forth in claim 9 having an arched forward deck whose sides join the under surface of the plane, its crest joining the vertex of the nose of the plane.

18. A flying boat of the character set forth in claim 9 having an arched forward deck whose sides join the under surface of the plane, its crest joining the top of the plane, and wherein the monoplanes are detachable from the hull with their under surfaces flush with the deck, the deck portion under the plane being at the angle of incidence of the plane.

19. In a monoplane flying boat the combination of a boat hull of elongated form having a bow terminating in a sharpv cutting edge and having a high stem forming with the keel of the boat a sharp inclination, the forward deck ofthe hull being elevated above the level of the aft deck, with the. monoplane wings directly attached to the hull and having thick sections at their junction therewith, the elevated fore deck merging into thewing leading edge vertex the latter being the central air-flow convergency point at horizontal flight.

20. A monoplane flying boat including a boat hull of elongated form having a forward deck which is elevated above the level of the aft deck, monoplane wings attached to the hull deck the peripheral edges of the fore deck being downwardly inclined in the rearward direction with reference to the rear deck to form an angle with the edges thereof less than 180.

21. Ina monoplane of the character set 

